I know it was on Slashdot (so you’ve probably already seen
it) but I have to mention this and file it under “UI”: TrailBlazer, a web browser (built on Apple’s WebKit, so it’s basically
Safari) with a 2D, branching interface to browser history. A thumbnail preview of each page you visit is captured for the history interface as well. Working on BeIA, Chris and I spent hours drawing these history diagrams on the whiteboard, trying to boil them down to some sane linear ordering for the browser component. It never occurred to us to just copy those whiteboard drawings into the product, but maybe that’s because we didn’t really have the horsepower to do so at the time (we were struggling to browse the web at 800×1024 on a 300 MHz Geode).